Sunday, November 7, 2010

Enhanced and Synthetic Flight Vision Systems

More advanced systems are coming into vogue, including the enhanced and synthetic flight vision systems. With each advance in technology the ability to operate aircraft in worse and worse conditions safely improves. A perfect example of operating an aircraft in close proximity to the ground in bad weather was the crash of the Tu-154 airplane at Smolensk in Russia. Despite warnings from ground controllers and advice to deviate to another airport, the pilots continued their attempts to land until the inevitable happened: the aircraft crashed.
The aircraft was designed in the 1960s and was not equipped with some of the modern technology presently available such as a Hud system, enhanced or synthetic vision, so the pilots had to rely upon conventional instrumentation and their own abilities to fly the aircraft to the runway.

The Kollsman EVS II All Weather Window® EFVS has been developed to improve the capability for commercial, business and military aircraft to execute precision and non-precision approaches and safely land in fog, rain, snow, and other reduced visibility conditions thereby reducing CFIT accidents. EVS II provides lower landing credit in accordance with current FAA and EASA EFVS regulations. The Kollsman EVS II is ideal for modern WAAS/SBAS RNP operations by providing a means to continue descent below decision height at all airports regardless of infrastructure and weather conditions. The Kollsman All Weather Window® EFVS also provides improved situational awareness during ground operations aiding in runway incursion accident reduction.

Enhanced flight vision systems place a real world visual image on top of a conformed image generated by an infrared camera mounted on the nose of the aircraft. The camera is to be placed as close to the pilot’s eye position in order to provide the proper visual cues to the pilot.
The FAA has only relaxed operating regulations allowing an aircraft with an EVS system installed to perform a Cat I approach to Cat II minimums. It is currently not legal to operate the aircraft below 100′ above ground level even if the EVS provides a clear visual image of the runway environment.
A Synthetic Vision System, on the other hand, uses terrain databases to create intuitive and realistic views of the outside environment. In this system the aircraft’s current flight path is computed along with the aircraft’s energy available and a view of the surrounding terrain.
This system uses a unique SVS symbol which displays a diminishing sideways ladder defining a tunnel in the sky through which the aircraft is flown in 3 dimensions. If the pilot can maintain the flight path vector along with the trajectory symbol the aircraft will fly the optimal path to touchdown.

Today a lot of this technology is finding its way into automobiles, enhancing safety for drivers in low light/visibility and night conditions. Once again drivers have found using HUDs in high light conditions while wearing sunglasses requires them to use non-polarized aviator sunglasses to avoid distortion or the inability to see the readouts properly.
Once again technology in aviation is leading the way in more than just aviation.

Until next time keep your wings straight and level Hersch!

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